The present invention relates to a metal backing plate structure for a liquid crystal display module and more particularly to a metal backing plate structure that is integrally formed with a ground protrusion and an improved form to facilitate installation of the liquid crystal display module and to enhance the structural strength of the metal frame.
In the developments for computer applications, the main stream of display screens have gradually shifted from high-radiation and high-electric power consumption cathode ray tubes (CRTs) to low-radiation and lower-electric power consumption Thin-Film Transistor Liquid Crystal Display (TFT-LCD) panels. It is well known that the Conventional LCD panel is a non-illuminant device and must be coupled with a back light source to achieve the displaying effect. In the art, the back light performance of the LCD panel directly affects the display quality, and so it is easy to see that the back light element for dominating the back light performance is one of important components in the LCD module.
In general, a conventional LCD module mainly includes a plastic frame, a liquid crystal panel, a back light module (including a plurality of thin films, an acrylic light guiding plate, a light source, and a reflection sheet), and a metal backing plate. Overlapping of the plastic frame and metal backing plate can be grouped into two types. The first type has a plastic frame located over the inner side of a metal backing plat, while the second type has the plastic frame located outside the metal backing plate.
FIG. 1 illustrates a first-type LCD module that has a plastic frame 10 located over the inner side and a metal backing plate 11 located at the outer side. This type of module has the advantage of directly coupling the metal backing plate 11 to an outer frame (not shown in the drawing) that includes ground capability for achieving excellent ground effect. However, this type of LCD module has to deploy the plastic frame 10 in an inverse manner during assembly, and consecutively the liquid crystal panel, film layers (not shown in the drawing), light source (not shown in the drawing) and other elements are assembled in this inverse manner. Apparently, the assembly work of the first type is troublesome. Moreover, for the plastic frame 10 has a center opening to house the window, the film layers may drop accidentally due to negligence during assembly and thus it is quite possible that element damages may occur while assembling the first type of the LCD module.
FIG. 2 illustrates the second-type LCD module that has the plastic frame 10 located outside the metal backing plate 11 located on the inner side. This type of LCD module is assembled by consecutively stacking the reflection sheet 13, the light guiding plate (not shown in the drawing), the light source 16, the film layers (not shown in the drawing), the plastic frame 10, the liquid crystal panel 14 and the outer frame 15 over the metal backing plate 11. Hence, the film layers can be securely assembled without accidentally dropping. However, it is noted that, in this type of LCD module, the metal backing plate 11 is completely encased in the plastic frame 10 and thus cannot couple directly with the grounding outer frame 15. Therefore, a separate ground metal protrusion 12 must be provided to bridge the outer frame 15 and the metal backing plate 11 so as to achieve the required grounding effect.
Refer now to FIG. 3 for a perspective view of the metal backing plate 11 of FIG. 2 and also an enlarged view upon a corner of the metal backing plate 11 that presents the end of the metal backing plate 11 for grounding. As shown, the metal backing plate 11 has a jutting section 31 located at a jutting corner 111 (at a corner periphery 30) formed by shearing. In mechanics, it is obvious that such type of fabrication for forming the jutting section 31 cannot provide sufficient structural strength. While subjected to a bending in an up-and-down direction, the jutting section 31 may incur permanent deformation or even result in fracture at the sharp corner 310.
As previously discussed, conventional metal backing plates 11 have a lot of shortcomings in assembly and utilization. Therefore, a need to make an improved metal backing plate that can facilitate assembly work for LCD modules and also enhance structural strength as well as the grounding convenience is obvious.
Accordingly, the primary object of the present invention is to provide a metal backing plate structure for a liquid crystal display (LCD) module that integrates a ground protrusion for directly coupling with a metal outer frame so as to simplify assembly work for the second-type of LCD module and to achieve better grounding effect.
Another object of the present invention is to provide a metal backing plate structure that presents a stronger strength by providing the metal backing plate with a smooth lateral side.
The metal backing plate structure of the present invention is adopted for the second type of LCD module that overlaps the plastic frame outside the metal backing plate. The metal backing plate with at least one lateral side is formed by pressing upon a flat metal sheet. The lateral side has at least one ground protrusion bent and extended by a predetermined length. While the metal backing plate is assembled with the plastic frame, the ground protrusion can penetrate through a corresponding aperture formed on the plastic frame. In a later assembling step, while an outer frame is assembled to an LCD module, the top end of the ground protrusion can directly contact with a shield rim of the outer frame so as to establish electrical connection between the outer frame and metal backing plate.
In order to prevent from serious stress concentration at a shearing point during pressing, the lateral side of the metal backing plate adjacent to the ground protrusion can adopt a smooth profile to improve the strength of the lateral side.
The metal backing plate of the present invention may be made of any conductive metal sheet, preferably an aluminum sheet.
The foregoing, as well as additional objects, features and advantages of the present invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.